Annular valve seat



June 2l, 1938.

J. zAGoRsm 2,121,464

ANNULAR VALVE SEAT 'original Filed July 31; 1935 nNvEN-rolz G1 W 'AT-VIV -the passage controlled by the valve.

UNlTED STATES.` PATENT OFFICEl AJohann Zagorski, Vienna, Austria Original application July 31, 1933, Serial No. 682,995. Divided and this application March l 16, 1934, Serial No. 715,833

1 claim. (ci. 251-167) l This application is a division of my' copending application, Serial No. 682,995, filed July 31, 1933.

This invention relates to the fixing in position of an yforming oi' a tight4 Joint about a y valve seat ring. It is already known that a hard seat having a collar or ilange may be provided by pressing the seat into an undercutv groove in 'This seat i'orms a part of the lateral delimiting surface of the passage wall. In the hitherto known types of seat ringsrhowever, a tight joint is obtained Aby the `collar or flange, because by pressing the material of the seatringinto the undercut groove in the casing this collar or flange is pressed into close contact with the casing. It is extremely diilicult to obtain an effectively tight joint in this manner, since the surfaces to be brought together must be absolutely smooth and true.- Furthermore, high quality steels of which hard seatings of this nature are made `have a higher coefficient of expansion than cast steel,

cast iron, or wrought iron. Therefore heating of l the parts loosens the seat and thus ycauses leaks.

The present inventiony provides a method of pressing hard seats of high quality steel having no collar or flange o! any kind, Iinto an underout groove in the wall oi.' the passage controlled by the valve. 'This is accomplished in such a manner that the annular seat is put into a state of high inherent tension which remains effective in pressing the ring with great force against the sides of the undercut groove in thevcasing.

Under the action of heat this lateral pressure is very considerably increased, the seating ring of high 'quality steel having a higher coeillcient oi expansion than the material of the casing which lmay be made. for example, of cast iron,

cast steel, or wrought iron. 'I'hus with highlysuperheated steam of temperatures up to 500 C.

and at pressures as high as atm. absolutely tight fitting of the valve seat is ensured.

The carrying out of the invention `is illustrated, by way ot example, in the accompanying drawing, in which: d

Fig. 1 shows a sectional view of. a seat ring according to the invention before the pressing of the same into position with a die.

Fig. 2 shows a sectional view of the ring oiy Figure lafter it has been pressed into place. 5

In order that the seat ring 8 shall iit absolutely tightly in the casing this ring is pressed, asindicatedin Fig. 2,-into an undercut groove 'l the upper portion of which is slightly tapered as at |0. The outer surface of the ring 6 has a simiw larly tapered portion i0 turned thereon for the necessary fraction of its height, and is otherwise cylindrical, while the inside of the ring' is ilrst cylindrical and then tapered to i'crm a conical surface I1 for a height corresponding to that of 15 rial displaced thereby is of slightly greater volume than that of the undercut groove 1, so that.

when the ring is pressed into position therel is 25y very considerable pressure p and p1 against the inner wall ci the casing 2. which pressure ensures a tight Joint in the manner indicated above.

What I claim is: an In a valve seat construction. a body having a bore, a counterbore at one end of the bore, the side wall of the counterbore having two` portions disposed at an angle to each other. meeting at a line intermediate the lower wall and the upper edge of the counterbore and flaring in opposite directions from said line. and a seat ring mounted in said counterbore and having iiared portions conforming to and tightly engaging the correspondingly flared portions of said sidewallto form a seal and securing means between the body and the seat ring. A

JOHANN ZAGORSKI. 

